Adjuvant activity of multimolecular complexes based on Glycyrrhiza glabra saponins, lipids, and influenza virus glycoproteins.

Numerous studies have shown that immunostimulatory complexes containing Quil-A saponin and various antigens are effective in stimulating the immune response and can be used as vaccine preparations for animals and humans. However, Quil-A saponin possesses toxicity and haemolytic activity. In the present work, a saponin-containing preparation named "Glabilox" was isolated from the roots of a Glycyrrhiza glabra L. plant by high-performance liquid chromatography (HPLC). The results showed that Glabilox has no toxicity or haemolytic activity and can form stable immunostimulatory complexes. Subcutaneous immunization of mice with an immunostimulating complex containing Glabilox and H7N1 influenza virus antigens stimulated high levels of humoral and cellular immunity. Vaccination of chickens with the same immunostimulating complex protected 100% of the animals after experimental infection with a homologous virus. Comparative studies showed that the immunogenic and protective activity of immunostimulatory complexes containing Quil-A and immunostimulatory complexes containing Glabilox are comparable to each other. The results of these studies indicated that Glycyrrhiza glabra saponins show great promise as safe and effective adjuvants.

Adjuvant activity of saponins from Kazakhstani plants on the immune responses to subunit influenza vaccine.

In recent years, there have been a number of reports on the successful use of immunostimulatory complexes with saponins and viral glycoproteins as veterinary vaccines and in clinical trials for human medicine. The saponins Algiox, Sapanox and Pangisan were isolated and purified by HPLC from Allochrusa gypsophiloides, Saponaria officinalis and Gypsophila paniculata plants in Kazakhstan and they proved to have low toxicity in experiments with mice, chickens and chicken embryos. Algiox, Sapanox and Pangisan can be used to create immunostimulatory complexes (ISCOMs) similar to saponin-Quil-A-containing ISCOMs both in structure and in immunostimulatory efficiency. The adjuvant effect of the obtained saponins was studied by subcutaneous injection of mice with ISCOMs containing these herbal saponins and lipids and glycoproteins of H7N1 influenza virus. Sapanox, Pangisan and Algiox from Kazakhstani plants of the family Caryophyllaceae could be considered an additional source of highly effective adjuvants not only for veterinary vaccines but also for human medicine.

[Molecular genetic characteristics of the newcastle disease virus velogenic strains isolated in Russia, Ukraine, Kazakhstan, and Kirghizia].

The F gene fragment of 79 Newcastle disease virus (NDV) strains isolated from domestic and synanthropic birds in Kazakhstan, Kirghizia, Ukraine, and Russia in 1993 to 2007 was comparatively analyzed. Phylogenetic analysis of test isolates and reference NDV strains obtained from the GenBank was carried out by polymerase chain reaction with subsequent sequencing and comparative analysis of 154-bp nucleotide sequences in the main functional region of the F gene. All newly characterized isolates belong to three NDV genotype VII subgroups: VIIa, VIIb, VIId. The results show it necessary to monitor of NDV strains isolated in the CIS countries since the spread of NDV among migratory and synanthropic birds (pigeons, crows, and jackdaws) poses a serious threat to commercial poultry industry.

Immunostimulatory complexes containing Eimeria tenella antigens and low toxicity plant saponins induce antibody response and provide protection from challenge in broiler chickens.

Immunostimulating complexes (ISCOMs) are unique multimolecular structures formed by encapsulating antigens, lipids and triterpene saponins and are one of the most successful antigen delivery systems for microbial antigens. In the current study, both the route of administration and the antigen concentration of ISCOMs, containing Eimeria tenella antigens and saponins from native plants, were evaluated in their ability to stimulate humoral immunity and to protect chickens against a challenge infection with E. tenella. Broiler chickens were immunized with ISCOM preparations containing E. tenella antigens and the purified saponins Gg6, Ah6 and Gp7 isolated from Glycyrrhiza glabra, Aesculus hippocastanum and Gipsophila paniculata, respectively. The effects of the route of administration, dose of antigen and type of saponin used for construction of ISCOMs were evaluated for ability to stimulate serum IgG and IgM and to protect chickens against a homologous challenge. A single intranasal immunization was the most effective route for administering ISCOMs although the in ovo route was also quite effective. Dose titration experiments demonstrated efficacy after single immunization with various ISCOM doses but maximum effects were observed when ISCOMs contain 5-10mug antigen. Immunization of birds by any of the three routes with E. tenella antigens alone or antigens mixed with alum hydroxide adjuvant resulted in lower serum antibody and reduced protection to challenge relative to immunization with ISCOMs. Overall the results of this study confirm that significant immunostimulation and protection to challenge are achieved by immunization of chickens with ISCOMs containing purified saponins and native E. tenella antigens and suggest that ISCOMs may be successfully used to develop a safe and effective vaccine for prevention of avian coccidiosis.

Immunostimulating complexes incorporating Eimeria tenella antigens and plant saponins as effective delivery system for coccidia vaccine immunization.

Immunostimulating complexes (ISCOMs) are unique, multimolecular structures formed by encapsulating antigens, lipids, and triterpene saponins of plant origin, and are an effective delivery system for various kinds of antigens. The uses of ISCOMs formulated with saponins from plants collected in Kazakhstan, with antigens from the poultry coccidian parasite Eimeria tenella, were evaluated for their potential use in developing a vaccine for control of avian coccidiosis. Saponins isolated from the plants Aesculus hippocastanum and Glycyrrhiza glabra were partially purified by HPLC. The saponin fractions obtained from HPLC were evaluated for toxicity in chickens and chicken embryos. The HPLC saponin fractions with the least toxicity, compared to a commercial saponin Quil A, were used to assemble ISCOMs. When chicks were immunized with ISCOMs prepared with saponins from Kazakhstan plants and E. tenella antigens, and then challenged with E. tenella oocysts, significant protection was conveyed compared to immunization with antigen alone. The results of this study indicate that ISCOMs formulated with saponins isolated from plants indigenous to Kazakhstan are an effective antigen delivery system which may be successfully used, with low toxicity, for preparation of highly immunogenic coccidia vaccine.

[Immunostimulating activity of a saponin-containing extract of Saponaria officinalis]. / Izuchenie immunostimuliruiushchei aktivnosti saponinsoderzhashchego ékstrakta Saponaria officinalis.

The immunostimulating activity of saponin-containing extract of Saponaria officinalis has been studied. Use of an S. officinalis extract in a concentration close to the critical concentration of saponin micella formation increased the immunogenicity of viral glycoproteins. The immunogenicity of glycoprotein complexes with S. officinalis was higher than the immunogenicity of intact virus and micellae of purified glycoproteins and was comparable to that of glycoprotein complexes with Quil A glycoside.

Assessment of dot-blot ELISA sensitivity on membrane sorbent using various peroxidase substrates.

The sensitivity of the peroxidase reaction in dot-blot ELISA significantly depends on the substrate. The highest sensitivity is observed using benzidine and diamine-phenol combinations as the substrates due to the reaction of the coupled oxidation (NADI).

[Interactions between Mycoplasma and human and animal viruses. Ultrastructural analysis]. / Vzaimodeistvie mikoplazm s virusami cheloveka i zhivotnykh. Ul'trastrukturnyi analiz.

Presented are the data on the ultrastructural analysis of interaction between mycoplasma and certain cancerogenic and infectious viruses in humans and animals. Revealed are spontaneous associations of mycoplasma with viruses of cattle leukemia, T-cell human leukemia and with a representative of Bunyaviruses. Immediate interaction of these agents is found possible. Simulated complexes of mycoplasma with infectious viruses are developed. Electron microscopy on supramolecular levels revealed immediate interaction of different agents in membranes. Some methodological procedures help to reveal that the interaction of M. pneumoniae and A. laidlawii with orthomyxo-, paramyxo and togavirus is of specific character and is realized as receptor ligand form due to the affinity in the receptor requirements of these pathogens. This property as well as a bequeath distribution and frequent association in respiratory infections enable one to suggest the possibility of their immediate interactions in a host body.

[Study of influenza virus hemagglutinin H3 avidity using monoclonal antibodies]. / Izuchenie avidnosti gemaggliutinina H3 virusa grippa s pomoshch'iu monoklonal'nykh antitel.

The results of a comparative study of the features of antigenic determinants of avid and non-avid variants of influenza virus hemagglutinin H3 and of the influence of the mode of antigen presentation on the degree of its avidity are presented. The avidity of influenza virus hemagglutinin was shown to be determined by the capacity of individual antigenic determinants to interaction with antibodies. The antigenic determinants of avid hemagglutinin possessing a high functional activity in interaction with antibodies may have the spatial configuration which does not change in different modes of the antigen presentation. Isolation of hemagglutinin from virions of non-avid virus variants may lead to increased functional activity of individual antigenic determinants (and the antigen molecule as a whole) probably due to an increased degree of exposure and/or complementarity of the determinants for active centres of antibody.

[Masking of HIV antigen by specific antibodies in a model experiment]. / Maskirovanie antigena virusa immunodefitsita cheloveka spetsificheskimi antitelami v model'nom éksperimente.

An immuno-diagnostic test system of competitive EIA detecting HIV antigen in a concentration up to 1 ng/ml has been developed. Using this system, a phenomenon of binding of HIV antigen by antibody in sera from infected persons consisting in masking of antigenic determinants was demonstrated. The "undetectability" of HIV antigen in the system of competitive EIA caused by this phenomenon is considered to be a model of clearance of antigen at the excess of antibody in vitro. The experimental results are in agreement with the suggestion that repeated HIV antigenemia occurs as a result of exhaustion of specific immune responses.